In the article "Marking of plastic pipes.Pipes based on polyethylene " I told about what the producers write on their products. There was superficially touched on the topic of materials. Today we will go into this topic. Pict.1 Cross-linked polyethylene pipes So, the main types of materials that are used for the production of plastic and metal-plastic pipes are: - Polyethylene PE ; - High density polyethylene PE-HD ; - cross-linked polyethylene PEX-a ; - cross-linked polyethylene PEX-b ; - cross-linked polyethylene PEX-c ; - polyethylene of raised temperature PE-RT . The first two materials do not have the qualities of heat resistance. Polyethylene has a branched molecular structure. And under the influence of temperature, its crystal lattice will collapse. Therefore, pipes made of such materials cann’t be use in systems with a working medium temperature higher than 70 ° C. Pict.2 Molecular structure of polyethylene PE To ensure that ...
Сантехнический мир в деталях